Rates of depressive disorders are especially high among the U.S. veteran population, and depressed patients are at greater risk for a number of negative social and health outcomes. Behavioral Activation (BA) is an efficacious treatment for depression, but little is known about its effect on well-established risk and maintenance factors for depression, including thwarted belongingness, perceived burdensomeness, and rumination. Thirty-two treatment-seeking veterans ( M _age  = 56.97; 87.5 % male; 68.8 % Black/African American) completed self-report measures before and after a 10-week group-based BA treatment for depression. Findings indicated thwarted belongingness and ruminative reflection subscale scores significantly decreased from pre- to post-treatment, whereas perceived burdensomeness and brooding subscale scores did not. These findings suggest that group-based BA may offer a cost-effective treatment option for depressed individuals, especially those with greater feelings of thwarted belongingness and more ruminative reflection. Future research would benefit from extending these findings, especially by incorporating a control group and utilizing a sample of younger non-veterans.